Method of and means for manufacturing sound absorbing material



G. M. THOMSON METHOD 0F AND MEANS FOR 'MANUFACTURING SOUND ABsoRBINGMATERIAL Aug. 29, 1933.

Filed Nov. 28, 1930 2 Sheets-Sheet 1 I I I l l l Il INVENTOQI GEORGE M.THOMSON ATTO RNEYS.

Patented Aug. 29, 1933 UNITED STATES PAT vENT ovl-"Fica IVIETHOD 0F AND'MEANS FOR RIANUFAC- TURING SOUND ABSORBTNG MATERIAL George MillervThomson, Caledonia, Ontario Canada Application November 2s, 193e serialNo. 498,895

Claims; (Cl. 154-28) 10 having a multiplicity of narrow wedge-shapedsive to staggered spaced points on opposite sides.

cells, and the present invention provides an advantageous method ofmanufacturing such a product.

'According to the present invention the sound absorbing material isproduced by applying adheof exiblematerial, such as asbestos paper, andthen producing a stack of such strips and allowing the adhesive to dry.The resulting product 0 can be readily expanded to any desired degree toproduce any predetermined width of cell vopening, by bending thematerial to a suitable curvature, applying adhesive to the concave faceoi'l the curved material, then applying a backing to the curvedface,'and then flattening the material.

A convenient method of continuously manufacturing the sound absorbingmaterial will now be described.

, Referring now to-the accompanying drawings, whichA illustrate, by wayof example, one convenient embodiment of the invention,

Figure 1 is a diagrammatic side elevation of part of the improvedapparatus,

Figure 2 is a plan view on the line 2-2 of Figure 1,

Figure 3 is a side elevation of another part of the apparatus on alarger scale,

' Figures 4 and 5 are side elevations illustrating subsequent steps inthe improved method of manufacturing sound absorbing material.

Figures 6 and 7 are plan views of the sound absorbing material producedby the method illustrated in the other figures, the material being showncontracted in Figure 6 and expanded in Figure 7, and l y Figure 8 is adiagrammatic perspective view ofthe adhesive-applying means shown inFigures 1 and 2.

According to the ilustrated form of the invention, a web of suitableflexible material 1, preferablvl asbestos paper, advances from a supplyroll-1a and passes successively over a guide roll 2, anadhesive-applying roll 3, guide rolls 4, guide roll 5, anadhesive-applying roll 6, guide roll 7, drive rolls 8 andbetweencrimping rolls 9.

The roll 3 is arranged to apply parallel lines or bands of adhesive 10to the surface 11 of the web of paper 1, while roll 6 isarranged toapply parallel lines of adhesive 12 to the surface 13 of the paper 1,the adhesive lines l2 being dis' posed midway between the lines 10 asshown in Figure 2. This is preferably accomplished by providingdistributing rolls 3a and 6a beneath the rolls 3 and 6 respectively.'Ihe rolls 3a and 6a dip into adhesive containers 3b and 6b and 35 thepairs of rolls 3. 3a and 6,. 6a are rotated by a suitable means, notshown, in the direction of the arrows in Figure 1. The rolls 3 and 6 areprovided with Scrapers 3c and 6c formed with notches 14 in theirscraping edges, as indicated 70 in Figure 8, the spacing and width ofthe notches being determined according to the desired spac-J ing andwidth of the lines of adhesive 10 and 12. The liquid adhesive is carriedup by rolls 3a and 6a and is transferred to the rolls 3 and 8, thethickness of the adhesive films transferred to the rolls 3 and 6 beingadjustable by varying thev distance between the rolls. For example, theaxles of the rolls 3 and-6 may be journalled in side frames, such as 17.The spacing of the rolls 3. and 3a, and 6 and 6a, may be adjusted toobtain the desired thickness of adhesive by means of screws 18.

block 15, supported upon springs 16 in slots in so The adhesive whichpasses through the slots 14 of. scrapers 3c and 6c is applied to thesurfaces 1l and 13, respectively, of the paper web 1, and the guiderolls 5 and 7, the drive rolls 8 and crimping rolls 9 are formed withannular grooves 90- 19 so as to avoid disturbance of the adhesivelines10 and 12.

The crimping rolls 9 fold or bend the web l into a zigzag formation, asindicated at A, and at this stage may be supported by any suitable meanssuch as an endless belt 20.

The crimped paper A is then manipulated to close up the folds thereofinto the form indi-1 cated at B, in which form the paper will be held assoon as the adhesive lines 10 and 12 dry. This operation may beperformed by the means indicated in Figure 3. Arcuate ngers21 are causedto oscillate about pivots 22 by means of rotating .cams 23, againstwhich the fingers are held in Figure 4.' The material B is fed betweentwo suitably spaced grinding wheels 26, which grind off the upper andlower surfaces of the material B and thus produce a material indicatedat C, which consists of a stack of rectangular strips of paper connectedto one another at staggered points on opposite sides of each strip. Aportion of the material C is shown in Figure 6 in which the lines ofconnection on one side of each strip are shown at 10 and on the oppositeside of each Vstrip at12.

The material C is next expanded to form the material indicated at D inFigure '1, the degree of expansion being determined in accordance withthe characteristics of' the sound waves to be absorbed, as referred tomore particularly in applicants copending. application No. 498,896.

u The expansion is preferably effected by the method illustrated inFigure 5. The contracted material C is placed on a cylindrical member2'1 with the paper strips extending parallel to the axis of thecylinder, so that the strips will tend to assume a radial position withrespect to the axis of the cylinder. The outer face ofthe material C isthus caused to assume the expanded condition illustrated (to anexaggerated extent) in Figure 7. Adhesive is then applied to the outeredges forming the curved outer face of the material C and a backing offlexible but inextensible ma ferial 28, such as paper, is applied. Thebacking 28 need not extend entirely over the face of the material, butmay consist of, say, three strips of paper, one along each edge of thematerial and another at the middle thereof. As soon as the adhesive hasdried the material is removed from the cylinder 27 and flattened and thefront face of the material then automatically assumes the same expandedcondition as the back face. Thus, by selecting a suitable diameter ofcylinder 27, in relationA to the thickness of the material C, anydesired degree of expansion can be readily effected,and permanently xedby applyingthe backing 28.

Many modifications within the scope of the appended claims may be madewithout departing from the invention.

What I claim is: l

1. A method of making sound absorbing material which comprises applyingadhesive atstaggered spaced points on opposite sides of flexiblematerial, producing a stack of rectangular strips of the exible materialwith the adhesive thus applied thereto, allowing the adhesive to dry,then expanding the resulting material to a definite predeterminedextent,.and securing said material in said definite expanded condition.

2. A method of making sound absorbing material which comprises applyingadhesive at staggered spaced pointswon opposite sides of vflexiblematerial, crimping said material transversely, closing the folds of saidcrimped material upon one another, removing the outer surfaces ofsaidclosed, crimped material, allowing the adhesive to dry, then expandingthe resulting material to a definite predetermined extent, and applyingan inextensible backing to one side of the expanded material.

3. A method of making sound absorbing materiaLwhich comprises applyingadhesive at staggered spaced points on opposite sides of flexiblematerial, producing a stack of rectangular strips of the flexiblematerial with the adhesive thus applied thereto, allowing the adhesiveto dry, then expanding the resulting material by bending said resultingmaterial over a cylindrical surface of predetermined radius, applying abacking of iiexible inextensible material to the outer face of the bentmaterial, and then fiattening the backed material.

4. A method of making sound absorbing material which comprisescontinuously advancinga web of flexible sheet material, applying spaced,parallel lines of liquid adhesive to one surface of said web, applyingsimilar spaced parallel lines of liquid adhesive to the other surface ofsaid web in staggered relation to the first mentioned lines of adhesive,crimping the webv laterally into a zigzag formation, closing the foldsof said allel lines of liquid adhesive to opposite sides of a web offlexible material, the adhesive lines on one side being staggered withrespect to those on the other side, crimping the iiexible material,closing the folds of the crimped material, allowing the adhesive linesto dry, grinding off thev outer faces of the closed crimped material, expanding the resulting product to a definite, predetermined extent, andsecuring said material in said definite expanded condition.

'6. A method as claimed in claim 5, wherein the closed, crimped materialis then expanded to form a multiplicity of double-wedge-shaped cells bybending `the closed crimped material to a curvature of predeterminedradius, applying a flexib1e.inextensible backing to the convex face ofthematerial and then flattening the backed material to cause thepreviously concave face to be expanded to the same extent as thepreviously convex face.

'7. A method as claimed in claim 5, wherein the adhesive is applied b ysupplying liquid adhesive to a roll engaged by the exible material,scraping from the roll all except spaced lines of adllesive, androtating the roll to move said lines of adhesive' continuously intocontact with said ilexible material.

. 8. A method as claimed in claim 5, wherein thev cept spaced lines ofadhesive, and adjusting the thickness of then transferred film ofadhesive by moving the distributing roll towards or 'away from thesupply roll.

9. Apparatus for making sound absorbing material comprising means forapplying staggered -spaced lines of adhesive to the opposite sides offlexible sheet material, means for then forming a stack of strips of theflexible material, means for expanding the resulting material to adefinite, predetermined extent and means for securing said material insaid definite expanded condition,

10. Apparatus for making sound absorbing matex-iai comprising means forcontinuously applying staggered spaced lines of adhesive to the oppositesides of a web of iiexible sheet material, means for continuouslyadvancing said web, means for crimping said web laterally, means forclosing the folds of said crimped material on to one another, means formaintaining the folds of condition.

GEORGE MILLER THOMSON.

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